Explorers

This is a list of explorers.
http://en.wikipedia.org/wiki/List_of_explorers

This is about explorers.
http://www.emints.org/ethemes/resources/S00001141.shtml

Presidents

This is a list of presidents
http://encarta.msn.com/media_461519285_761571294_-1_1/media.html

This is a description of president.
http://en.wikipedia.org/wiki/President